An early airway apparatus for assisting in artificial respiration comprised an arcuate, open-ended tubular member which was adapted to be inserted into the trachea. The tubular member carried an external, inflatable resilient sleeve near the distal end thereof for effecting a seal with the inner wall of the trachea. The use of this early airway for moving air through the trachea into and out of the respiratory orifices required trained personnel, and therefore, was limited primarily to emergency rooms in hospitals.
In U.S. Pat. Nos. 3,683,908 and 3,841,319 is described another airway whose tubular member has a closed distal end. A plurality of openings are provided in the wall of the tubular member between the distal end and the proximal or mouthpiece end thereof. The tubular member is shaped to be inserted into the esophagus leading to the stomach rather than through the trachea leading to the lungs. An inflatable sleeve is carried by the tubular member near the distal end thereof for making a seal with the esophagus. Forced air passes from the tubular member through the openings and into the lungs of the respiratory system. To prevent the forced air from venting externally through the nose and mouth, there is provided a mask which is intended to seal the nose and mouth and to force the pumped air into the channels of the respiratory system.
But, if the close-ended tubular member were to be accidentally inserted into the trachea, as it may occasionally happen, the pumped air would move into the stomach instead of the lungs which may result in the death of the patient. This results from the airway having a closed end and the expandable sleeve sealing off the trachea.
Since no artificial respiration can take place, instead of filling the lungs with air, the tubular member would inflate the stomach, resulting in the expansion thereof followed by vomiting. When the administrator of the artificial respiration becomes aware of the accidental insertion of the tubular member into the trachea, he may attempt to deflate the sleeve, remove the tubular member from the trachea, and insert it into the esophagus. In the meantime, even if the operation is successful, the contents of the stomach could enter into the lungs.
The preceding problem is vaguely made reference to in said U.S. Pat. No. 3,683,908 (Col. 4, lines 32-35) which suggests making the outer diameter of the tubular member "of oral external-section." If this were to be done, presumably the diameter of the tubular member would be sufficiently large so as to prevent it from becoming inserted into the trachea. But a tube having such an oral external-section might damage the esophagus into which it is to be inserted.
In addition to the above described problem occurring when the tubular member is misguided into the trachea, there is another problem concerning the required mask which does not always provide an effective seal with the face because the face dimensions vary from patient to patient.
Another problem can be encountered when such a tubular member is inserted into the esophagus. During the process of resuscitation vomiting can occur. With vomiting high pressures are exerted from the stomach up through the esophagus. When the tubular member is in the esophagus with the sleeve inflated such that the vomit could not exit, excessive pressure becomes exerted at the junction zone between the stomach and esophagus. This pressure can be so high as to tear the esophagus away from the stomach with resulting hemorrhage.
In our copending patent application Ser. No. 907,066 is described an airway which overcomes the above described problems. The airway of this invention constitutes a substantial improvement and is simpler in construction and use, as will become apparent from the following description.